The present invention relates to devices for administering, delivering, injecting or dispensing substances, and to methods of making and using such devices. More particularly, it relates to such devices, including, for example, injection devices, injection pens, etc., for dispensing medicinal substances, such as insulin or hormones, in selected amounts or doses. More particularly, the present invention relates to an injection device with a volume for accommodating a product or substance for administration, with a piston to act upon the product within the volume, and with a stopper which can be arranged between the end of the piston facing the product and the product within the volume.